Traffic actuated signaling apparatus



Ap 1 1942- H. A'., WILCOX 2,279,896

TRAFFIC ACTUATED SIGNALING APPARATUS Filed Dec. 15, 1939 lNVENTOR HAM? vA. VV/LCOX dzpa ATTORNEY Patented Apr. 14, 1942 waste TRAFFIC ACTUATED'SIGNALING APPARATUS Harry A. Wilcox, Norwalk, Conn, assignor toAutomatic Signal Corporation, East Norwalk, Conn., a corporation ofDelaware 1 Application December 15, 1939, Serial No. 309,314

12 Claims.

The present invention relates generally to trafiic control apparatus ofthe traflic actuated type employed for the control of right of Way oftrafiic on streets, highways and roads. This invention relates moreparticularly to improved traffic signal control apparatus of this typeprimarily for use at each of a plurality of intersections of cross roadsalong a main road to provide coordinated signaling at the severalintersections in predetermined time relation.

Systems have been known for some time in the prior art in which thesignal controllers at a series of intersections along a main road arearranged to accord right of way to the main and cross roads alternatelyat periodic intervals at each intersection in accordance with aprearranged progressive or synchronized pattern for the entire series ofintersections, so that groups or platoons of traffic moving on the mainroad at the predetermined speed for which the system is designed will inthe case of a progressive system pass through all the intersectionswithout stopping, and will in the case of the synchronized system movefor long distances along the main road before right of way isinterrupted, with such interruption of right of way being made at allintersections simultaneously.

It has also been known in the prior art that the controllers at suchintersections may be of the trafi'ic actuated type in which traflicdetectors are placed for actuation by cross road traific approaching theintersection and right of way is not transferred from the main road tothe cross road at an intersection except in response to actuation of thetraific detector. system in order to maintain assured main road right ofway periods at the several intersections in the desired time relationfor movement of main road traific the transfer of right of way from themain road'to the cross road in response to cross road traffic actuationis permitted to occur only at the end of what would be the main roadright of way period at each intersection were the controller there to beof the periodic, nontraflic-actuated type.

The coordinated traffic actuated system can be visualized as having acontinuously operating background cycle for all signal controllers atall intersections in the system in predetermined time relation, and thesignal controller at any one intersection is connected to be operatedthrough a local signal cycle in accord with the background cycle inresponse to trafiic actuation at that intersection.

One type of periodic trafiic signal controller In this type of in theprior art employs a signal switching camshaft of the step-by-step typeand a solenoid operated ratcheting device for stepping the camshaftthrough its signal cycle, the solenoid being operated momentarily fromtime to time over an operating circuit including contacts operated bypins in a continuously rotating dial. In such type of controller onerevolution of the dial d'etermines the total time length of the signalcycle and the pins are placed in desired positions in the rotating dialso as to divide the total cycle for the several steps of the camshaft.

In accordance with one form of the present invention a trafiic actuatedswitch is interposed in the operating circuit for the solenoid in acontroller of this type, between the solenoid and the contacts operatedonly by a particular pin for operating the camshaft at a particularpoint in its cycle; which point is preferably chosen as the end or nearthe end of the main road right of way period where the trafiic actuatedswitch is actuated by traffic in the'cross road for example,

so that the camshaft cycle can be initiated from its main road right ofway rest position only at the predetermined point at which theparticular pin is located in "the cycle of the continuously rotatingdial; and thus an improved traffic actuated signaling apparatus isprovided which is adapted to form a unit in a coordinated system havinga fixed total cyc1e,'and which apparatus provides for safeand readyflexibility of adjustment of the several signal periods of the cyclewithout the possibility of exceeding the total cycle by such adjustmentso as to interfere with coordination with other units. p It is a generalobject of the invention to provide an improved traffic signalingapparatus in which a step-by-step cyclic signal controller is initiatedto provide a signal cycle under control of and at a predetermined pointin the cycle of acyclic stepping device in response to trafficactuation.

It is also an object of the invention to provide an improved trafiicactuated signaling apparatus of a type in which the total length andsubdivision of the signal cycle into predetermined parts is fixed by onerotary member and the combinations of signals to be displayed in theseveral different parts of the cycle is determined by a second rotarymember controlled by the first member responsive to traflic actuation.

Other objects will appear from the disclosure and claims below.

Apparatus embodying the invention will now 2' 1 be described and itsoperation explained in connection with the accompanying drawing.

On the left side of the drawing is represented to change, and thecontrol apparatus I for the signals.

readily comprehended from the following more detailed description.

Considering for example the intersection of roads A and B shown at theleft side of the figure of drawing, vehicle actuated detectors DI,

D2 are located in the cross road approaches to the intersection. Thesemay be of the pressure operated pavement type which operate during thepassage'of a vehicle across them to close an electric circuit. Suitablephoto-electric and electro-magnetic detecting devices and other Trafiicdetectors DI and D2 are located "in 1 the cross road At the right sideof the drawing is shown an other intersection along the main roadA, the

B to be actuated bytraffic therein.

one shown being at a cross road C and provided T with signals, detectorsand controllers II which is similar in construction to controller I.Both controllers together with all others which may comprise the systemare connected toa common AC power source.

- Considering controller I atthe intersection of V A'and Broads'briefiy, the controller or timer is of the rotating dial type, therotating dial or disc being driven at constant speed by a syn chronoustype motor M having the samecycle time as the other controller motorsand keeping closely in step with such other motors as for example withmotor M'-shown, asboth are furnished with power from a common AC powersupply to all the motors.

By means of pins or studs in the rotating disc and a linking arrangementshown herein to be comprised of contacts adapted to be actuated by thepins to energize the solenoid S of a solenoidoperated ratchetingmechanism, a camshaft CS is operated step-by-step through a cycle ofoperation. Contacts operatedby cams on the shaft control the display ofsignal indications. Al-

though'the disc rotates continuously the aforementioned stepping of thecamshaft through a cycle of signal indications is not initiated until aunit of trafiic on the cross road approaches the intersection to actuatea detector located in ornear the cross road approach and affects thecontroller to prepare a circuit for stepping the camshaft from theresting position at the first subsequent moving of the disc through apredetermined point in the cycle of the'latter. The camshaft thereafteris notched through one cycle and back to a resting position by action ofthepins mentioned, and in its cycle of operation the camshaft causes thetransfer of right of way, with the usual yellow clearance or'changeperiods intervening, from the main road to the cross road and back tothe main road where the right of way remains until" another crossroaddetector actuation has prepared the circuitafor again stepping thecamshaft from its resting position and the rotating disc has againreached the predetermined or synchronizing point in its cycle.

Provision is made to lock-in or rememberactuations of the :cross roaddetectors by vehicles which actuate the detector so late in the cross'road right of way display period that they have insufficient time tocross the intersection or which actuate the detector duringthe main roadright of way period, thus preparing the wayfor another cycle of camshaftoperation in which right way is again transferred to the cross road. r

The details of construction and operation of an embodiment of thecontroller will be more ing: continuously a disc l0 either directly orby a system of gearing. A plurality of pins or studs Hare removablymounted in the face of disc 10 and cooperate with a pair of contacts Hito close a circuit through the contacts and another pin l2 alsoremovably mounted in the face of the disc independent of pins Hcooperates. in similar fashion with the contact pair I4.

The disc is preferably provided with a series of holes 9 near itsperiphery and the pinsmay be fitted into selected holes as desired todetermine the division of the fixed total time cycle into appropriatesignal periods by stepping the camshaftCS by actuation of the solenoidS. The camshaft-CS has an appropriate matching arrangement of cams toprovide the several different signal combinations and the distributionof pins in the continuously rotating disc detervance the camshaftstep-by-step through its cycle by means of aratchet 20 on the camshaftand a pawl 15, energization and deenergization of the solenoid movingthe camshaft one step. Energizing the solenoid causes the pawl arm l6,pivoted at I], to be pulled down against stop 8| against tension inspring 3, causing the pawl IE to engage another tooth IS on ratchet 20which is prevented from moving backwards by dead pawl 23. Subsequentdeenergization of solenoid S. allows spring IE to contract and returnarm 16 against stop 82 thus advancing the camshaft counterclockwise onestep or tooth in ratchet 20.

Two circuits are provided for energizing the solenoid S. One of thesecircuits includes the pair of contacts l3 which are adapted momentarilyto be closed by each of the pins II in succession as each one of thepins H is rotated .through the top of its circular path of move- !4whichis closed once in each cycleof the disc by the synchronizing pinl2the purpose of which will subsequently appear.

The disclosed embodiment of the controller shows a 6 position camshaftand accordingly there are provided 5 pins II for energizing the solenoidto step the camshaft through all but one of its positions from which oneposition only the pin l2 and its cooperating contactpair ll areeffective to advance the camshaft. 'more camshaft positions are desireda greater Obviously if number of pins II are inserted in disc I keepingthe number of pins II always one less than the total number of camshaftpositions, and corresponding teeth on ratchet 20.

In series with contacts I3 is a pair of contacts 2| which are closed bycam 3| in all positions of the cam-shaft except position 2, which istermed the A green rest position, in which pins II and contacts I3 arerendered ineffective to advance the camshaft by the opening of contacts2|. In all positions of the shaft except position 2 however, a circuitis completed to energize solenoid S upon the momentary closure ofcontacts I3 by one of the pins II from AC minus wire IOI over wires 48,49, contacts 2|, wire 44, contacts I3, wires 43, 42 and 40 and upon theimmediate opening of contacts I3 to deenergize solenoid S and advancethe camshaft one tooth or position.

"A chart of camshaft positions is included in the lower left portion ofthe drawing and indicates by means of an X in a square that the contacts2|, 22, 2429 are closed in a particular camshaft position.

Let it be assumed that the camshaft is standing in position 2, the Agreen rest position, in which contacts 24 and 29 operated by cams 34 and39 are closed completing circuits from AC plus power, wire I 90 overwires I4 and I9, respectively through A road green signal AG and B roadred signal BR respectively to AC minus power. As described abovecontacts I3 and pins 'II are ineffective to advance the camshaft fromthis position 2 and the right of way remains accorded to the main roadby energization of the AG signal.

A relay R is adapted upon actuation of one of the cross road traflicdetectors DI or D2 to be energized from AC minus via wire 58 detector DIand wire 56 or wires 58, 51 detector D2, thence through Wires 55, 53,relay R and wire 54 to AC plus. Such an actuation is remembered orlocked-in by the holding circuit of relay R via wires 52, make contactrI, wire 5|, contacts 22 closed by cam 32 in all positions of thecamshaft except position 4, Wire 50 to AC' minus.

-When a detector actuation has energized and locked in relay R a circuitis prepared from AC minus over wires 48, 41, make contact r2, wire 46,over contacts I4, wires 45, 42, and 49 to solenoid S to energizesolenoid S upon the next closure of contacts I4 by pin I2 and thecamshaft is thereby advanced to its next position, position 3. The pointon the cycle of dial II] at which contacts I4 become closed may forsimplicity be termed the synchronizing point and it will be noted thatboth a traffic actuation must have been locked in and the synchronizingpoint of the dial cycle must have been reached in order for the camshaft to advance to position 3.

With reference to the cam chart it will be seen that in position 3contacts 24 are broken and contacts 25 are made thus replacing the AGsignal indication with the AY or change indication to A road traflic.When the dial III has been suificiently rotated for the next pin II toclose contacts I3 and reopen them thus energizing momentarily solenoid Sthe camshaft is advanced to position 4.

In position 4 cam contacts 25 and 29 are broken extinguishing the mainroad yellow change signal AY and the cross road red signal BR and rightof way is accorded to the cross road. Cam contacts 26 and 21 are closedto illuminate the cross road green BG and the main road red AR. Contacts22 are opened in this position thus deenergizing relay R.

A period of B road right of way ensues until the next pin II is rotatedto close contacts I3 in turn momentarily energizing solenoid S toadvance camshaft to position 5.

In position 5 there is no change of signal indications, the total crossroad B right of way period being the sum of the time periods ofpositions 4 and 5. In this position, however, contacts 22 are againclosed by cam 32 so that actuations of the detectors DI, D2 whichmomentarily energize relay R are effective to maintain relay R energizedto cause another cycle of operation of the camshaft and retransfer ofright of way to the cross road when contacts I4 are next closed bysynchronizing pin l2. Accordingly vehicles crossing the detectors inposition 5, the last portion of the cross road right of way period andwhich have insuflicient time to pass the intersection are remembered andright of way is subsequently again accorded to the cross road to allowsuch vehicles to proceed. Position 5 is occupied ordinarily for only afew seconds and is terminated by the revolving of the next pin II tocause closure of contacts I3 advancing the camshaft in the mannerdescribed.

Contacts 21 are opened in position 6 extinguishing the cross road greensignal BG and contacts 28 are closed to illuminate the cross thesolenoid S advancing the camshaft into po- 7 sition 2, the AG restposition once more.

In position 2 the signal indications remain the same as in position 4but contacts 2| operated by cam 3| are open so that as pointed out abovethe solenoid operating circuit through contact pair I3 is ineffective tomove the camshaft from this position.

If upon the next closure of contacts I4 by pin I2 no actuation haslocked in relay R the camshaft CS remains in this position causing rightof way to be displayed to the main road continuously for an entire cycleof dial I9 until contacts I4 are again closed by pin I2 or for a longerperiod, equal to an integral number of revolutions of the dial it, untilsuch time as contacts I4 are closed by synchronizing pin I2 and avehicle actuation has locked in relay R.

The dial I II has the same cycle length as the dial III at all otherintersections of the group comprising the coordinated system and is keptcontinuously in step with dial III at any other intersection by thesynchronous type motors M, M which are supplied from the same powersource. Accordingly the position of pin I2 on dial II] in relation tothe corresponding pin I2 in dial I0 in another controller determines thetime relation between the interruption of right of way on the main roadat the first intersection with interruption of right of way on the mainroad at the second. In a system of the so-called synchronized type inwhich interruption of right of way to the main road takes placesimultaneously .at all 'intersections'of the group the pin l2 and'itsoffset to provide'uninterrupted travel of platoons of traffic movingalong, the main road may be .established by locatingthe pins I2, l2 atthe several intersections at. desired spacingsaround their respectivedials so that each controller will provide the proper offset or timeperiod before the point at whichright of way transfer from the. mainroad is permitted from-a zero or reference point which may be markedcorrespond- Thus it will be seen that any ingly on each dial. desiredtime relationship between the time of transfer of right of .way from themain road at the several intersections maybe obtained'by the relativepositioning of the several pins [2, I2,

and H, H.

As an example of the ofiset adjustment of pins l2 and I2 the pin. I2 isshown in a more advanced positionin Controller II than the pin I I2 inController I.

If it is desired at any intersection that right of way be transferred tothe cross road whether or not there has been actuation of the cross roaddetector the switch M (or corresponding switch BI) is closed againstcontact 62 so that plus power is supplied directly via wires 63, 60through contact pair M to the solenoid S to advance the camshaft uponoperation of contacts l4 independently of operation of relay R; Anydesired allotment of the total time cycl of the dial Ill to the severalsignal'periods may be made by suitably locating the pins H which areremovably positioned in the face of the dial. Accordinglythe length ofthe cross road right of way period may be different at differentintersections without disturbing the settings for transfer of right ofway from the main road at each intersection required by the progressiveor synchronized program utilized.

Adjustment of the total time cycle of the dials I0, l may be made in anysuitable manner as for example by introducing gears of different sizesin the drive of the dials so long as the total time cycle of each dialis the same as that of all the other dials.

It will be observed that the pin 12 in the controller, together with thecam 3| and contact 2| which interrupts the operation of the camshaft bypins H in camshaft position 2, resynchronizes the camshaft CS with dial,l 0 in every cycle of the camshaft. For example if one of the pins llshould temporarily not effect proper movement of the camshaft thuscausing the camshaft to be out of step with the dial and causingimproper timing of the remaining signal periods in one cycle, thecamshaft will be resynchronized with the dial when the camshaft is nextadvanced from position 2 by action of the long pin I2 to form than thatof controller. I.. 'The wiring of controller II for its solenoid Sincludes the contacts l3 operated by pins. I l, and'the cam con- .tactsZl in one circuit for solenoid S and in-- cludes contacts l4 operated bythe long pin l2 and the traffic actuated relay contact T2 in anothercircuit for. its solenoid and these several elements correspond with thesimilar elements in controller I, butthe arrangement of these elementsin the solenoid circuit is somewhat different, and the circuits for thesolenoid in controller II will therefore be traced briefly below.

The circuit for operation of solenoid S" by action of pins H may betraced from A0 minus power wire l0! via wire B5,.solenoid S, wires 86,81, 88, cam contacts 24', wire 85, pin operated contacts l3,, wires .90and 9! to AC plus power Wire I60. The circuit for operating solenoid S'by action of pin 12' may betraced from AC minus power wire HH' via wire85, solenoid S, wires 86, B7, B2, contacts r2, wire 93, pin operatedcontacts 14, wires 94, 91 -to AC plus power wire I60. I Y

In thisalternate form of wiring used in controller II the switch 6 Icorresponding to switch Moi controller I, cross connects wires 81, 93when the switchis closed, to shunt contacts r2 when it is desired tohave controller II act as a cyclically operated periodic controllerinstead of a traific actuated type of controller.

Also for the purpose of illustration the camshaft GS of controller II isshown in position 4, partway through its cycle, as a result of previoustraflic actuation of one of the detectors in the cross road'C. In theposition shown the cam contact 22' is open so as to interrupt the lockin circuit of relay R and release this relay from the effect of theprevious traflic actuation, so that the camshaft CS will stop when itreaches the rest position #2 unless a further trafiic actuation occurs.

Summarizing, from the above description it will be seen that the presentinvention provides a controller of novel and simplified design for usein coordinated traffic control systems for a plurality of intersections.A number of controllers of this type when used to make up such acoordinated system provide great operating flexibility both in respectto the length of the several timed signal 'periods at each intersectionand the relative times of certain signal changes at all theintersections when the controllers are used as vehicle actuatedor,non-vehicle actuated timers. Any desired relationship between thetimes of certain signal changes at the several intersections may beobtained even although no interconnecting wires are required other thanthe connection of all controllers to a common AC power source.

Each controller itself is of simple design of the rotating dial typehaving a number of pins in the dial which through a linking arrangementactuate a camshaft controlling the signal indications. As shown hereinthe linking "arrangement may comprise a solenoid-operatedratchet andpawl mechanism having two solenoid energizing circuits, One such circuitembracing a pair of contacts closed at a predetermined point once ineach cycle of the dial, in definite relationship at all intersections ofa group, initiates a cycle of operation of the camshaft if a vehicle hasactuated a vehicle detector in the approach to the intersection. Theother solenoid energizing circuit includes contacts operated by otherpins in the dial to maintain operation of the camshaft through the restof its cycle one such operation has been initiated. Accordingly themovement of the camshaft through a, cycle of signal changes in responseto traffic actuation is maintained in synchronism with operation of thero-' tating disc, and since the several rotating discs are maintained insynchronism the signal changes at the intersections are maintained indesired relationship.

It will be appreciated by those skilled in the art that the circuitclosers might be mounted on a rotating disc to be operated by stationarypins set in fixed holes, in lieu of the stationary circuit closersoperated by pins in the holes of a rotary disc as shown in the presentembodiment.

It will also be appreciated'by those skilled in the art that other formsof signal indications can be employed in lieu of the yellow signalindications in camshaft positions 3 and 6 for the respective streets, orthat two camshaft positions could be employed in lieu of the one for thehange indication for each street so that two stages of changeindications could be provided for each street such as a dark signalperiod on one street followed by a red signal period for both streetsfor example at each change of right of way, with a corresponding changein the number of pins in dial I and in the number of teeth in theratchet 20 and in the contour of the cams on camshaft CS.

It will also be understood that the number of holes 9 shown in the discI0 is for simplicity of illustration only and that ordinarily aconsiderably larger number of closely spaced holes would be employed togive finer adjustment.

It will be further understood that other detectors may be connected inparallel with detectors DI, D2 and that push buttons or the like can beconnected similarly for operation by pedestrians.

In this connection it will be understood that although the presentdisclosure represents a preferred embodiment of the invention this andother rearrangements of the parts or changes in the details of the partsmay be made without departing from the spirit of the invention asdefined by the claims.

I claim:

1. In a traffic signal system for the intersection of a main road and across road, a step-by-step right of way signaling controller adapted tobe operated through a cycle including right of way signal conditions forthe respective roads, a continuously operating synchronous motor, acircuit closer operated periodically by said motor, an electromagneticstepping device for operating said controller one step at a time, meansoperating said stepping device at spaced time intervals through all ofsaid signaling cycle except one condition in which right of way isindicated to the main road, means to be actuated by trailic in the crossroad including a switch closed by such actuation, and means including anoperating circuit having said circuit closer and said switch in seriesfor operating said stepping device in said one condition responsive toclosure of said switch and circuit closer.

2. In traflic control apparatus for the intersection of a main road anda cross road having traffic actuated means for the cross road and astep-by-step right of way signaling mechanism operable through a cycleof right of way signal indications for the respective roads responsiveto actuation of the traflic actuated means, means operativelyassociating said mechanism with said traffic actuated means including ashaft, a motor rotating said shaft, a circuit closer operatedperiodically by said shaft as the latter rotates, a second rotatableshaft, switches arranged to be operated by said second shaft in apredetermined sequence of switch combinations to provide for the rightof way signaling cycle as said second shaft rotates, another switchopened by said second shaft in the main road right of way part of itscycle and closed in all other parts of its cycle, a second circuitcloser operated periodically by the first mentioned shaft, said firstshaft and circuit closer being arranged for operating said first circuitcloser a plurality of times corresponding to one less than the number ofthe difierent switch combinations in the cycle of the second shaftduring a cycle of rotation of the first shaft and for operation of thesecond circuit closer once in each cycle of rotation of said firstshaft, a switch closed by actuation of said trafiic actuated means,step-by-step means for operating said second shaft from one switchcombination to another in its cycle when operated, an operating circuitfor said step-by-step means including said first circuit closer and saidanother switch, and another operating circuit for said step-bystep meansincluding said second circuit closer and the trafiic actuated switch.

3. In a traffic control apparatus as in claim 2, electromagnetic holdingmeans connected to said traffic actuated means to maintain said traificactuated switch closed after closure by trafiic actuation when operated,and an operating circuit for said electromagnetic means including anadditional switch opened by said second shaft in the cross road right ofway part of its cycle to release said trafiic actuated switch and closedin all other parts of the cycle.

4. In a trafiic control system for an intersection of a main road and across road having traffic actuated means for the cross road, asynchronous motor and a right of way signaling controller adapted to beoperated through a cycle including right of way signal conditions forthe respective roads in sequence at its intersection responsive toactuation of said traffic actuated means and in predetermined timerelation with its associated motor under control of the latter; saidcontroller comprising a step-by-step rotary signal switching mechanismproviding the cycle of right of way signal conditions, an operatingdevice for said mechanism to operate the latter from one step to anotherin its cycle responsive to momentary actuation, a circuit closer, a dialrotated by said motor, pins placed in said dial so as to actuate saidcircuit closer momentarily one at a time as said dial is rotated, asecond circuit closer placed out of range of said pins, an additionalpin in said dial for actuating said second circuit closer momentarily ata predetermined point in the cycle of rotation of said dial, anoperating circuit for actuating said operating device including thefirst circuit closer and a switch closed by said mechanism through allthe cycle of the latter except one condition in which right of way isindicated to the main road and another operating circuit for actuatingsaid operating device including said second circuit closer and a switchclosed by actuation of said traflic actuated means for the cross road, aholding means for maintaining the trafiic actuated switch closed aftertrafiic actuation and as long as said holding means is operated, and anoperating circuit for said holding means including a switch closed bysaid mechanism in all its cycle except one condition in which right ofway is indicated to the cross road.

5. In a traffic control system for an -intersection of a main road and across road having trafiic actuated means forthe cross road, asynchronous motor, and a right of way signaling controller adapted to beoperated through a cycle including two successive right of way signalconditions for the respective roads in sequence at its intersectionresponsive to actuation-of said trafiic actuated means and inpredetermined time relation with its associated motor under control ofthe latter; said controller comprising a stepby-step rotary signalswitching mechanism providing the cycle of right of way signalconditions, anoperating device for said mechanism to operate the latterfrom one step to another in its cycle responsive to momentary actuation,a circuit closer, a dial rotated by said motor, pins placed in said dialso as to actuate said circuit closer momentarily one at a time as saiddial is rotated, a second circuit closer placed out of range ofsaidpins, an additional pin in said dial for actuating said second circuitcloser momentarily at a predetermined point in the cycle of rotationofsaid dial, an operating circuit for said operating device including thefirst circuit closer and a switch closed by -said mechanism in allconditionsof its cycle except the second successive right of waycondition for the main road, and another operating circuit foractuationof said operating device including said second circuit closer and aswitch closed by actuation of traflic actuated means for the cross road,a holding means for maintaining the traflic actuated switch closed aftertrafiic-actuation-and as long as said holding means is operated, andanoperating circuit for said holding means including a switch closed bysaidmechanism in allconditions of its cycle except the first right-ofway conditionifor .the cross road. a

6. In a trafiic control system for a main road anda cross road havingmeans actuated by trafiic on the cross road and a right of way signalingmechanism adapted to be operated through a cycle including .rightiofwaysignaling periods for each road, said mechanism including a platemember having a plurality of spaced holes circularly arranged, a circuitcloser, a continuously operating timing motor providing relative rotarymovement between said .plate member and said circuit closer, a pinplaced in a selected one of said holes, a step-by-step cyclic signalingswitch having a plurality of steps inits cycle including right of waysignaling steps for the vrespective roads, an electromagnetic devicemomentarily actuable for operating said cyclic switch one step at atime, relay means connected to said traflic actuated means to beoperated responsive to trafflc actuation thereof to connect saidelectromagnetic device for momentary actuation by said circuit closer asthe latteris actuated by said pinto operate said cyclic switch at onestep of its cycle in which right of way is signaled to the main: roadand thereafter to be released in preparation for any subsequent trafficactuation, and means including other pins placed in selected others :ofsaid holes and connected with said cyclic switch to actuate saidelectromagnetic device to operate said cyclic switch through theremainder of its cycle after such operation in said one step.

7. In a traflic control system fora main road anda crossroad havingmeans. actuated by traffic on the .crossroad andarightof way signalingmechanism adapted to be operated through a cycle including right of waysignaling periods for each road, said mechanism including a platemember, a circuit closer, "a continuously operating timing motorproviding relative rotary movement between said plate member and saidcircuit closer, pins spaced in selected positions in said plate memberto actuate said circuit closer momentarily during such rotary movement,a stepby-step cyclic signaling switch having a plurality of steps in itscycle including right of way signaling steps for the respective roads,an electromagnetic device momentarily actuable for operating said cyclicswitch .one step at a time, circuit means controlled by said cycleswitch to connect said electromagnetic device for momentary actuation byfirst said circuit closer in all steps of said signal cycle except onein which right of way is signaled to the main road and to disconnectsaid electromagnetic device in said one step, a second circuit closerplaced out -0 range of actuation by said pins, an additional p' in saidplate member placed and adapted to actuate said second circuit closeronce in each cycle of rotary movement, relay means connected tosaid'traflic actuated means to be operated responsive to trafiicactuation thereof to connect said electromagnetic device for momentaryactuation by said second circuit closer as the latter is closedmomentarily by action of said additional pin during such rotary movementto operate said cyclic switch at said one step of its cycle andthereafter to release in preparation for another actuation of thetraffic actuated means.

8. In a traffic control system for the intersection of a main road and'across road, a continuously rotating disc having a pluralityof spacedholes in acircle concentric to its-axis-of rotation, pins placed inselected holes of said disc, a circuit closer placed to be operated bysaid pins, a step-by-step cyclic signal controller having a cycle ofsignaling steps including separate steps for right of way to therespective roads and intervening steps for right of way changeindications, anelectromagnetic ratchet'device for operating saidcontroller one step ata-time, a switch member closed by said cyclicsignal controller in all except one of said controller steps in whichone step right of way is indicated to the main road, an operatingcircuit 'for said electromagneticdevice including said-circuit closerand said switch member, another pin placed in 'said disc, a secondcircuit closer placed was to -be operated onlyiby said another pinonceineach cycle of said disc, trafiic actuated meansin the cross road, aswitch connected "to be closed by said trafficactuated means responsive"to traffic actuation thereof, and an auxiliary operating circuit forsaid electromagnetic device including said last named switch and saidsecond circuit closer.

'9. A trafficcontrol system'for amain roadand cross road includingelectric right of way sig-' nals -for the respective Toads, meansactuatable by tra'fiic inthe' crossroad, a step-by-step cyclic switchactuat'able for operating said signals through a cycle including right"of way periods for the respective roads, an electromagnetic "(levicefor so actuating said'cyclic switch, a continuously operating motoradisc rotated by'said motor, pins 'adjustably spaced in said disc, acircuit closerlin position to be oper'ated momentarily by each of saidpins'as said disc is rotated, a second circuit closer, imposition not tobe actuated by said pins, "an-auxiliary pin in said disc in position tooperate said second circuit closer at one point in each cycle ofrotation of said disc, a relay, a third circuit closer opened by saidcyclic switch only in one step of the latter near the end of the mainroad right of way period, a fourth circuit closer operated by operationof said relay, a normal operating circuit for said electromagneticdevice including the first and third circuit closers in series, anauxiliary operating circuit for said electromagnetic device in-v cludingsaid second circuit closer and said fourth circuit closer in series, anoperating circuit for said relay connected with said traffic actuatablemeans to operate said relay responsive to trafiic actuation, anothercircuit closer opened by said cyclic switch only in one step of itscycle during the cross road right of way period, and a lock-in circuitfor said relay including said other circuit closer.

10. In a traffic right of way signaling apparatus for road intersectionshaving one rotary member providing a cycle of right of way signalingpositions to determine several combinations of signaling indications tobe displayed in the several positions of the cycle and a second rotarymember having a number of actuating elements adjustable in relativeposition on said member to determine a total length and subdivision of atime cycle into at least as many parts as the number of said signalingpositions, means including a trafic actuated device associated with oneof the intersecting roads to connect said second rotary member to saidfirst rotary member responsive to traffic actuation of said device foroperation of said first rotary member through its cycle by saidactuating elements to provide a right of way signaling period fortrafiic actuating said device.

11. In a street traffic right of way signaling apparatus the combinationof a rotary signal controller having a cycle of operating positions toprovide for a plurality of separate right of way signaling conditions insuch cycle, a step-- by-step driving device adapted to be operatedmomentarily to rotate said controller from one position to another insaid cycle, a shaft, a mog tor connected to rotate said shaft, a circuitcloser arranged to be operated by said shaft at spaced intervals aplurality of times in one cycle of rotation of said shaft, switchesforming a part of said controller and operated cyclically as saidcontroller rotates, an operating circuit for said driving deviceincluding said circuit closer and one of said switches open in one rightof way position of the cycle of said controller and closed through theremainder of such cycle, a second circuit closer arranged to be operatedmomentarily by said shaft at a predetermined point in its cycle ofrotation, traffic actuated means including a switch closed responsive toactuation by trafiic, an operating circuit for said.

driving device including said second circuit closer and said trafiicactuated switch for operating said driving device at said one positionof said controller cycle, a holding means for maintaining said trafficactuated switch closed after actuation thereof by trafiic and as long assaid holding means is operated and an operating circuit for said holdingmeans including one of said switches opened only in another position ofthe cycle of said controller coresponding to a right of way signalingcondition for traffic actuating said traffic actuated switch.

12. A traffic control system for a main road and cross road includingelectric right of way signals for the respective roads, means actuatableby tramc in the cross road, a step-by-step cyclic switch actuatable foroperating said signals through cycle including right of way periods forthe respective roads, an electromagnetic device for so actuating saidcyclic switch, a continuously operating motor, a shaft rotated by saidmotor, a circuit closer operated momentarily a plurality of times ineach cycle of rotation of said shaft, a second circuit closer operatedby said shaft once in each cycle of rotation of said shaft, a relay, athird circuit closer opened by said cyclic switch only in one step ofthe latter near the end of the main road right of way period, a fourthcircuit closer operated by operation of said relay, a normal operatingcircuit for said electromagnetic device including the first and thirdcircuit closers in series, an auxiliary operating circuit for saidelectromagnetic device including said second circuit closer and saidfourth circuit closer in series, an operating circuit for said relayconnected with said traflic actuatable means to operate said relayresponsive to trafiic actuation, another circuit closer opened by saidcyclic switch only in one step of its cycle during the cross road rightof way period, and a locking circuit for said relay including said othercircuit closer.

- HARRY A. WILCOX.

